Phonograph driving mechanism



D. W. ALLIS.

PHONOGRAPH DRIVING MECHANISM.

APPLICATION FILED FEB. I. 1918.

1 $I'3 5,@@9Q Patented Apr. 6, 192 190 2 SHEETS-SHEET I Ffiy 4a Tyweamfa 7 Jamie? w c/iZZ w 0. w. ALLIS.

PHONOGRAPH DRIVING MECHANISM.

APPLICATION FILED FEB. 1, I9I8.

1,335,809. Patented Apr. 6, 1920.

2 SHEETSSHEET 2.

Zwaziar Jeri-e7 w. CJZZ (15 f may.

UNITED STATES PATENT OFFICE.

DEXTER W. ALLIS, OF WHITMAN, MASSACHUSETTS, ASSIGNOR TO ARTHUR M. BREWSTER, OF BOSTON, MASSACHUSETTS.

PHONOGRAPI-I DRIVING MECHANISM.

Specification of Letters Patent.

Patented Apr. 6, 1920.

Application filed February 1, 1918. Serial No. 214,821.

To all whom it may concern Be it known that I, DEXTER W. ALLIs, a citizen of the United States, and resident of \Vhitman, in the county of Plymouth and State of Massachusetts, have invented an Improvement in Phonograph Driving Mechanism, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

My invention is an improved phonograph driving mechanism and the object of the invention is to improve and perfect such apparatus, particularly to render the driving of the record carrying platform noiseless, eflicient, and with a simple and economical construction which will run smoothly and effectively at all times without danger of getting out of order.

My present invention contemplates the provision of novel means to support and hold the record carrying platform; means to utilize an electrically driven motor employing the shaft of the motor as the direct driving means to rotate the platform; and the provision of novel means to enable the connections from said motor shaft to the platform to maintain a constant driving tension, while following any unevenness or wabbling of the platform itself during said rotation. Further features of the invention consist in the arrangement of a yielding friction driving medium to rotate the platform, adjustable means to secure said yielding friction driving medium in position, the speed governor and means to regulate the action of the same, and novel mechanism permitting a yielding and flexible driving action between the friction driving member and the motor shaft. whereby the motor is rigidly fixed in position and yet that portion of the shaft carrying the friction driving medium is allowed freedom of movement in all directions.

Other important features and advantages, details of construction and novel combinations of parts will be hereinafter more fully pointed out and claimed.

Referring to the drawings illustrating a preferred embodiment of the invention Figure 1 is a view partly in cross sectlon of my novel phonograph driving mechanism;

Fig. 2 is a plan view;

Fig. 3 is a detailed view on an enlarged scale of the brake controlling device;

Fig. 4 is a view, enlarged, on the line 44 of Fig. 1;

And Fig. 5 is an enlarged view, partly in cross section of the flexible joint or drive between the motor shaft and the friction drive shaft.

It will be appreciated that in prior phonograph driving mechanism it is customary to drive the rotating platform from a central shaft which is geared to the motor, the platform resting and wedging downwardly onto the central shaft, bringing the entire weight of the same upon the geared connections, and'necessarily causing undue noise, friction and rendering any oiling of the gears difficult and therefore seldom attended to by the ordinary operator, viz., the public. Such prior construction is of the type shown, for example, by U. S. Patent No. 1,246,823, dated Nov. 13, 1917. In carrying out my present invention of a substantially noiseless construction, I provide an antifriction bearing of novel form and mounting for the revolving platform, supporting the same entirely from the driving device which is applied from a yielding friction member adjacent the outer periphery of the platform. This construction permits me to have an efficient central support for the platform, preferably a ball bearing not requiring oiling. and I eliminate all gears and geared connections.

Referring to the drawings, the usual phonograph box inclosing same is indicated at 1, to which a bracket or brackets 2 are secured carrying the plate 3 extending into the center of the box sufliciently to provide a central axial support 4 for the platform 5 carrying the record disk. The plate 3 also has a depending flange 6 to which the motor 7 may be secured, or anyother convenient arrangement to support the motor could be made. I prefer to form the central axial support 4 as a tubular socket and position in the bottom of said socket a hardened steel ball bearing 8, on which the post 9, secured to the platform 5, rests. In order to have as nearly an anti-friction hearing as possible, I may fit within the bottom of the post 9 a hardened steel pin, shown at 10, which bears directly upon the single uppermost point of the ball 8, these two hardened steel surfaces presenting a minimum of friction as the post 9 and itsplatform rotate upon the axial point of contact between the member 10 and the ball 8. This construction of the. platform 5 with the post 9 secured thereto resting in a long bearing socket 4, is a novel feature in phonograph mountings, and insures steadier rotation of the platform 5, preventing the same from wabbling or uneven rotative movement, thus eliminating a frequent difficulty in former constructions wherein the platform 5 simply fitted over a conical surface in the top of the supporting post, giving but a short bearing therefor.

center the record disk is formed on the platform In order to prevent removal of the platform 5, I cut an annular groove as shown at 13 in the post 9 to receive the end of a threaded screw 14 set in a corresponding threaded socket in the side of the tubular socket 4.

The motor 7 may be secured or positioned in any desired angular relation, as slightly employed, but as a I prefer to utilize inclined substantially as illustrated in Fig. 1 with the shaft 15 of said motor resting against a thrust ball bearing 16 at one end, and projecting slightly at the other end. I provide an extension for this shaft 15 as shown at 17 to reach from the end of the shaft 15 to the vicinity of the outer edge of the platform 15, with a universal joint connection between said two shafts 15 and 17. a novel type of combined universal joint and flexible drive, as shown in enlarged detai in Fig. 5. To this end I provide a conical recess or socket 18 in the outer end of the shaft .15 and taper the corresponding end 19 of the shaft 17 forming said tapered end 19 on a more acute conical angle than that of the socket end 18, thus allowing for a considerable range of angular movement in all directions, and eliminating friction, both shafts touching at a single point. A coiled spring 20, having one end affixed to the shaft 15 as shown at 21, and the other end to the shaft 17 as shown at 22, which spring is wound under tension to hold the two shafts in firm contact and unites the same, thereby providing a yielding retaining and resilient driving means in combination with the universal joint construction just described. This universal. joint and resilient driving construction is of special value and utility in my noiseless phonograph driving mechanism. It will be appreciated that any other universal joint of well known type may he means of reducing friction, rendering same noiseless and giving an elastic drive from the fixed motor shaft 15 to the shaft 17 which must be flexible and angularly moved during the transmission of power therethrough, the joint herein shown is preferable.

yielding tension,

A central stem 12 to hold and r To support the shaft 17 and hold it under I apply a leaf spring 25 secured by a screw 26 to the plate 3 and with an adjusting screw 27 to give desired tension thereon, threaded through the plate 3 in appropriate position. As it may be desired to have the motor 7 at one side of the shaft 9, and the drive axially opposite, I make the spring 25 of sufficient width to span the hub 4, an enlarged aperture 28 in said spring enabling it to fit over the tube4. The outer end of the spring 25 is flanged at 29 to fit upon the bushing 30 through which the shaft 17 extends. This bushing is preferably made with rims 31 and 32 at opposite ends, and felt pads or washers 33 and 34 are sprung or fitted over the rims 31 and 32 respectively onto the bushing, these pads containing oil, recesses 35, 35, through the bushing supplying lubricant from the pads to the bearing of said shaft 17.

Adjustably fitted on the end of the shaft 17 is a cupshaped member 36, with its hub 37 constituting a bearing therefor on the shaft and carrying a set screw 38 to hold the member 36 in position. This member carries the friction driving medium 40, preferably in the form of a washer with a central recess fitted over the projecting end of the shaft 17 and being glued or otherwise secured in a cupshaped member 36. This medium 40 constitutes the friction driving surface between the shaft 17 and the under part of the platform 5, being braced and held under tension thereagainst by the action of the leaf spring 25. "It is desirable to have this friction medium of yielding material, and while it is feasible to employ any yielding substance, such as leather, felt, fiber, rubber or the like, I have discovered that this friction medium made of a viscol residuum, known as art gum, possesses peculiarly efficient qualities for this medium. The use of this art gum, besides being noiseless and providing the desired amount of yield, tenacity, and positive non-slipping driving friction, gives a certain amount of lubrication and is at all times resilient and absolutely noiseless. Leather, fiber and the like become hardened and are of limited life or usefulness in this position, and the same faults are found with rubber and fiber. On the contrary, the art gum, when thus supported in the cupshaped member 36, and employed as the friction driving medium, seems to be practically indestructible, while retaining its resiliency, self-lubricating qualities and perernor and speed control devices and these are also utilized in my present invention with a view to have the same simple, efiicient and noiseless. To this end I extend the plate 3 sufficiently beyond the tube 4, as shown at 41, with the end portions cut therefrom and depressed at right angles to constitute lugs 42, 42 (see Fig. 4), these shaft 17, and in position to bear against a disk 55. This spring 46 is pivotal secured to the shaft 44 by a screw 4 and the arms are thus adapted to swing toward and from the disk 55 by a slight relative movement of the shaft 43 and also to permit said arms to pivot on the screw '49 to automatically-adjust or seat upon the said disk 55. I prefer to apply to the arms 47 and 48 felt pads 50 and 51 respectively, clamping the ends of said arms about the respective pads, as shown at 52 and 53. These pads may be oil-soaked and will constitute the adjustable brakes on the disk 55 to regulate the speed of rotation of the shaft 17. The disk 55 is mounted on a sliding hub 56, and is secured to a collar 57 fixed to said shaft by a set' screw 58, by spring members 59, 59, 59, each member carrying a weight 60, 60. This construction constitutes an automatic governor of well known type, the increasing speed of rotation of the shaft 17 causing the disk- 55 to slide toward the fixed collar 57 by the centrifugal action of the weights 60 and consequent bending outward of the springs 59, 59, bringing said disk 55 into contact with the friction pads 50 and 51.

To adjust the friction pads as desired for the regulation of speed, I position near the outer end of 44 a bracket 70, secured to the box 1 and carrying a thumb screw 61 bearing downwardly with its end engaging a recess 62 in the outer end portion of said shaft 44. A spring 63 between the bracket 60 and the shaft 44 holds said shaft upwardly against the thrust of the thumb screw 61, as clearly shown in Fig. 3. This bracket may be just outside of the periphery of the platform 5, in convenient position for manipulation. The current supply wires 65 and 66 lead into the motor through a bushing 67 and thence to any desired terminals or source of power. It will be noted that my entire phonograph driving mech anism is entirely concealed and protected under the platform; that the motor can be positioned at any point convenient, and at any angle; that gears of all kind areieliminated; that an anti-friction and firmlyfisgpportingbearing for the disk carryin plat form is provided; that a novel type 0 noiseless and friction driving medium is employed; and that the driving shaft in direct continuation with the motor shaft is flexibly driven and angularly and 'yieldingly sustained in friction-driving-engagement with the platform, while a convenient, simple and efficient governor and speed control are also arranged. My invention is applicable to existing phonographs, requiring but a slight change and being readily installed when the driving gears, etc., are removed. By the elimination of friction to a minimum, Ican utilize a lighter, more economical and less powerful motor, preferably employing a small compact motor with a novel winding, which, however, is not an essential to the present invention and is not, therefore, further explained. The entire apparatus is free from any possible binding, noise-creating, or undue wearing action.

My invention is further described and defined in the form of claims as follows: 1. Apparatus of the kind described, comprising a talking machine record platform, a pivotal mounting for said platform, a motor rigidly mounted and a driving shaft having a flexible portion connecting said motor to said platform to rotate same.

2. Apparatus of the kind described, comprising a talking machine record platform, a pivotal mounting for said platform, a motor rigidly mounted, a flexible driving shaft connected to said motor and extending to the periphery of the platform to rotate the same, in combination with yielding means to, hold that portion of the shaft adjacent the platform tensioned toward the platform.

3. Apparatus of the kind described, comprising a talking machine record platform, a pivotal mounting for said platform, a motor having a shaft, and a flexible driving shaft connected to said motor shaft by a universal joint and extending to the pe-' riphery of the platform to rotate the same, and yielding means adapted to hold the flexible driving shaft into driving contact .with said platform.

4. Apparatus of the kind described, comprising a rotatable platform to receive a talking machine record, a motor having a drive shaft, said motor being supported under the platform, a shaft operatively connected to the motor shaft by a flexible joint at one end, a yielding friction driving medium at the other end of said shaft,-and yieldingly a djustable means to hold the friction driving medium in contact with the platform.

a 5. Driving mechanism for a talking machine, consisting in a rotary platform having a pivotal supporting post integral therewith, and resting on an anti-friction support a motor mounted rigidly at one side of said post, a shaft flexibly connected to 'the motor and carrying an adjustable friction driving member, in position to engage the said platform underneath its outer periphery, and means to hold said friction driving member in yielding contact with 10 the under side'of said platform.

6. Driving mechanism for a talking machine, consisting in a rotary platform having a pivotal supporting post integral therewith, a motor having a drive shaft mounted at one side of said post, a shaft flexible connected to the motor shaft and carrying an adjustable friction driving member, in position to engage the said platform underneath its outer periphery, said friction driving medium consisting in a mass of art gum.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

DEXTER W. ALLIS. Witnesses:

ARTHUR M. BREWSTER, JAMES R. HODDER. 

